Danfoss VLT Micro Drive PK18 Design Manual page 15

Safety and Conformity
100%
2 2
80%
50%
25%
12,5%
Illustration 2.3 Laws of Proportionally
Q 1 n 1
Flow :
=
Q 2 n 2
H 1
Pressure :
=
H 2
(
P 1 n 1
Power : =
P 2 n 2
2.5.4 Comparison of Energy Savings
The Danfoss frequency converter solution offers major
savings compared with traditional energy saving solutions.
This is because the frequency converter is able to control
fan speed according to thermal load on the system and
the fact that the frequency converter has a built-in facility
that enables the frequency converter to function as a
Building Management System, BMS.
Illustration 2.5 shows typical energy savings obtainable
with 3 well-known solutions when fan volume is reduced
to i.e. 60%.
As the graph shows, more than 50% energy savings can be
achieved in typical applications.
14
VLT Micro Drive Design Guide
Flow ~n
Pressure ~n
3
Power ~n
50% 80% 100%
( )
n 1
2
n 2
)
3
MG02K102 - VLT
Discharge
damper
2
n
Costlier installation
Illustration 2.4 The Three Common Energy Saving Systems
100
80
60
40
20
0
0
Illustration 2.5 Energy Savings
Discharge dampers reduce power consumption somewhat.
Inlet Guide Vans offer a 40% reduction but are expensive
to install. The Danfoss frequency converter solution
reduces energy consumption with more than 50% and is
easy to install.
®
is a registered Danfoss trademark
Less energy savings
Maximum energy savings
IGV
Discharge Damper Solution
IGV Solution
VLT Solution
60 0 60
Volume %
0 60